/Engine/Plugins/Online/OnlineFramework/Source/LoginFlow/Public/LoginFlowManager.h
Register an online subsystem with the login flow factory (call at startup)
whether or not the login flow was successfully added
virtual bool AddLoginFlow ( [FName](API\Runtime\Core\UObject\FName) OnlineIdentifier, const [FOnDisplayPopup](API\Plugins\LoginFlow\ILoginFlowManager\FOnDisplayPopup) & InPopupDelegate, const [FOnDisplayPopup](API\Plugins\LoginFlow\ILoginFlowManager\FOnDisplayPopup) & InCreationFlowPopupDelegate, bool bPersistCookies, bool bConsumeInput )